George f



(No Model.)

G. P. OASE. CORE LIPTER FOR ANNULAR ROGK DRILLS.

Patemtd` Mar. 28, 18u82.

"""uuxlllIlllllllllllllI Hill,"-

UNITED STATES I PATENT OFFI'CE.

GEORGE F. CASE, OF CLAREMONT, NEW HAMPSHIRE, ASSIG-NOR TO THE SULLIVAN MACHINE COMPANY, OF SAME PLACE.

CORE-LIFTER FORANNULAR ROCK-DRILLS.

SPECIFICATION forming part of Letters Patent No. 255,719, dated March 28, 1882,

Application tiled December 31,1881. (No model.)

To all whom it may concern:

Beit known that I, GEORGE F. CASE, of Claremont, in thecounty ot' Sullivan and State of New Hampshire, have invented a new and Improved Core-Lifter forAnnularRock-Drills; and I do hereby declare that the following is a full and 'exact description of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

My invention relates to an improvement in core-lifters particularly adapted tobe employed in connection with annular drills" for boring rock or other material, and whose purposeis the same as that set forth in Letters Patent No. 247,303, granted to myself September 20,

- 1881. l Its novelty consists principally in the combined construction and arrangementofits componentparts, andthe simplicity with which itso effectivelypertbrms its work, all as more fully hereinafter set forth and claimed.

For the better understanding ot' my invention, and to enable those skilled in itsrelative art to know howto construct and use the same, I will proceed to fully describeit with reference to the accompanying drawings, in which- Figure lds a longitudinal section thereof', Fig. 2, a cross-section on -the line m x of the same, Fig. 3, a longitudinal section of core-retainer modified in construction, and Fig. 4 a plan View of the same.

Like letters refer to corresponding parts in each figure. t

In the drawings, Arepresents the drill-head, (in which the cutting-points are inserted,) screwed upon the lower end ot' a tube, B, which in turn is screwed upon the lower end of the drill-rod C, of' usual construction. The upper end ofthe drill head is curved or rounded, as shown in Fig. l, for a purpose hereinafter explained. y

The device D, for grasping and retaining the core, consists of a solid ring of metal, provided with long depending prongs or springs b, whose lower ends are enlarged and made wed ge shape, as shown in Figs. 1 and 3, to accommodate themselves to the upper rounded end of the drill-head, for a purpose that will hereinafter be readily perceived. This ring, with its depending prongs or springs, is located in the recess of the tubing B formed by the, shoulders a a of the drill-rod C and the upper rounded end ofthe drillhead A. Within this recess the said ring, with its prongs or springs, has movement up and down, which movement is terminated in `either direction by the shoulders a a and the upper rounded end ot' the drill-head A, above referred to.

It is immaterial in regard to operation (as it is the same) whether the prongs or springs I) of the riugD be cast integral therewith or made separate and secured thereto by means of bolts or rivets, as shown in the moditication, Figs.

t 3 and 4. It is only a matter of convenience or desire. When'the drill is advanced andthe work of boring commences the ring D and its prongs or springs b hug the core, but permit it to pass up through them into the rod C, the downward movement ot' the drill naturally causing the said ring, with its prongs or springs, to be pressed up under the shoulders a a vof the rod C. NVhen thedesireddepthis reached and the drill is withdrawn the ring D falls,

causing the enlarged and wedge-shaped ends ofthe prongs or springs b to enter the curved or rounded end ot' the drill-head, which presses them tightly against the core, so as, 4when the core is broken, to grasp and retain iti the tube while the drill is being withdrawn from the hole.

What I claim, and desire to secure by Letters Patent, is-

In a core-lifter, the combination, with the drill-rod and its head, curved or rounded at its upper end, substantially as described and shown, ofthe metallic ring or band D, provided withV the depending prongs or springs b, enlarged and made wedge shape at their lower ends, substantially as described, shown, and for the purpose set forth.

This specitication signed and witnessed this l llthday 0I" November, 1881.

G. F. CASE. Witnesses:

JOEL F. RAYNsEoED, CHARLES H. CLARK. 

